High pitched sound while braking

[abdulhaque]

Hi all,

I have noticed a high pitched sound as long as I am braking on an upright position, so if front of car higher than rear. As soon as I let go of the brakes, the sound stops. This sound is not heard if braked while the car is braked on a level or down right position, so if front of car lower than rear. It is a multitronic A6 from 2010, front wheel drive. Any ideas?

Thanks

[lynalldiscovery]

Does it make the noise at a standstill?
I ask as wifes last car an A4 did this and it was the servo, not dear but a little fiddly to fit, hers was only when you pushed the pedal and was a whistle sounding noise.

[abdulhaque]

Yes I can normally start hearing it at standstill position only when braked in upright position, the sound may be present as soon as I brake, but can't tell as I can't easily hear it while the car is slowing down to a stop. It is quite a faint high pitch sound.